On a winter day in 2013, it was so cold at Lambeau field, home of the NFL’s Green Bay Packers, that the stadium’s beer and soda machines froze. The frigid temperatures, however, didn’t stop some fans from showing up to the game wearing nothing but body paint and foam cheese on their heads. In another instance of fan madness, a husband and wife bet on a Packers versus Bears football game, the loser of which would be shocked by a taser. The wife’s team lost, and although you might have thought her husband wouldn’t go through with it, he shocked her not once but three times.

After reading stories like these, you might be worried by what a hard look at sports could reveal about who we are and what we value. But in their new book, This is Your Brain on Sports, L. Jon Wertheim, executive editor of Sports Illustrated, and Sam Sommers, professor of psychology at Tufts University, show just how important sports are to understanding human behavior and human nature. Through the lens of psychology, neuroscience, and behavioral economics, Wertheim and Sommers examine the ways sports influence the way we see ourselves and our world.

I recently spoke with Sommers about his new book. We discussed whether or not sports can promote world peace, the moral hypocrisy of fandom, and why it is that we launch ourselves through the air for cheap t-shirts shot from cannons.

Seth Stancroff: Your book describes the fanatical behavior of sports fans—they paint their faces, go shirtless in the middle of winter, and make bets which, as you describe in the book, can involve eating bagels covered in chest hair. The famous ESPN slogan tells us: “It’s not crazy, it’s sports,” but that sounds pretty crazy. What’s going on in the minds of these impassioned fans?

Sam: At some level, the mission of the book is to demystify a bit of that “sports is just craziness” business. Sure there are extreme examples with the chest hair sandwich bet and things like that, and of course there are other organizations to which people, unfortunately, subject themselves to some fairly unusual if not at times demeaning and dangerous behaviors to join, but what we’re trying to do with the book is talk about the ways in which the world of sports sheds some light on human nature more generally. We humans are social animals, we are driven by the need for affiliation. We very easily slip into a tribal “us versus them” mindset in viewing the world around us and sports is in many respects no different along those lines.

To try to figure out whether consciousness existed at all in a patient, physicians had to pick something that was both familiar and resonant with these individuals, and they turned to sports. They turned to tennis.

Seth: The subtitle of the book reads: “The science of underdogs, the value of rivalry, and what we can learn from the t-shirt cannon.” What can we learn from the t-shirt cannon? What’s going through the mind of the fan who’s launching himself through the air to get a crappy t-shirt?

Sam: These crappy t-shirts could be three sizes too big [and] you wouldn’t spend three dollars for [them] in a store. But when you show up to the game, there’s arousal-inducing music and lighting. All of the sudden you’re tracing this wadded up t-shirt that you feel like you need to box people out to grab. What we talk about in the book is the consumer psychology of it. Two critical aspects of it are that it’s free—we’re very attracted to free. There’s a big difference between free and even five cents. Also they’re scarce. If everyone got one of these who walked into the arena, it would not have that same value, but they’re scarce and there’s some effort involved. You really have to fight for one of these sometimes, and so when you get one you feel lucky, you feel as if you’ve earned it. It’s almost like a trophy at that point.

Seth: Coaches today frequently find themselves on the “hot seat.” They’re under constant pressure from media, management, and fans to perform at high levels in very short periods of time, resulting in very little job security. Why is the coach’s seat so hot?

Sam: We talk a lot in book about the fact the coach’s seat is always hot these days. In the NFL, it takes usually until [the] third or fourth season until a coach has a winning record and the team scores more points than it gives up. But if you look at the data, it suggests that the average NFL coach doesn’t last past three or four seasons. [He] gets fired and they bring someone new in. We talk about that in terms of action bias—this idea that teams often feel like they need to do something. Standing pat and waiting patiently doesn’t always sit well. We have this bias to think “well I should at least do something.” If you look at the data from the world of business, companies fall victim to the same thing. When a company changes CEOs, that company’s bottom line often doesn’t improve at the start. In fact, it sometimes stagnates or even goes down a little bit because there’s a startup cost associated with bringing someone new in. It’s not to suggest coaches should never get fired, but if you look at the data, teams seem to be a little too trigger happy these days.

Seth: Many people think that sports competitions like the Olympics or the World Cup have the power to unite people and lead to peaceful relations between countries. Your book explains that, although it is appealing, this idea is more complex than we recognize. Is it true that sports promote peace?

Sam:There’s some interesting data on the World Cup. It turns out that teams that qualify for the World Cup, by some operational definitions at least, have more interstate military disputes in the few years that follow than the teams who don’t qualify. And for that matter, winding up in the same group as another nation in the first round of play in the World Cup tends to promote or predict more antagonistic relationships. It’s not necessarily that we’re suggesting that the World Cup is source of all the world’s ills, but it’s not this panacea magical cure-all.

When you put yourself in competition with another group, it is going to exaggerate some of these us versus them, in-group out-group tendencies that we have. It seems to be the case [that] international sports competition can at times be beneficial for relationships within a country—unite people with a common enemy. But there’s something to be said for the idea that [when] you’ve got international tension to begin with, throwing a high-stakes competition on that can be fuel to the fire. There are clearly examples historically of lower-stakes athletic events leading to some positive outcomes—ping pong diplomacy and so forth. The argument we make in the book is that it’s a much more complicated story than maybe the International Olympic Committee or FIFA might want to us to believe.

“Loyalty to any one sports team is pretty hard to justify because the players are always changing…You’re actually rooting for the clothes when you get right down to it.” -Jerry Seinfeld

Seth: Sports can reveal hypocritical behavior and moral inconsistencies, especially our willingness to judge athletes’ actions, often off the field, differently based on which team they play for. What is the psychology behind our inconsistent moral standards?

Sam: We are remarkably flexible when it comes to our moral compass. It’s not just the world of sports, it works in politics. If you’re a registered democrat and a republican does something you’re outraged, but if a democrat does the same thing perhaps not as much. On the one hand, it makes us look like hypocrites and less like consistent individuals, but I think what’s really interesting is sports might be the one domain in which we’re most likely to acknowledge our hypocrisy. In other domains we’re not really willing to say “oh of course if I were a democrat I’d feel differently.” We really believe we’re being totally calculative and rational. Sports at some level seems like it’s a liberating place for many of us. To be able to admit the old Jerry Seinfeld line that at some level we’re rooting for laundry—the name of the city on the shirt. It’s interesting, maybe at some level liberating, to admit to our hypocrisy in the sports context when we don’t otherwise.

Seth: Each chapter of your book is devoted to a different way sports can teach us about human nature. In your opinion, what is the most profound connection you draw between sports and the human condition?

Sam:The last chapter of the book is about the researchers and clinicians who struggle with perhaps the biggest human question of all: what is consciousness and where does life begin and end? We’re talking about the physicians who are encountering individuals in a persistent vegetative state trying to determine when life has begun and ends and whether someone’s conscious or not. Making those decisions is not easy. What one group of researchers decided to do was try to look for sort of signs of some sort of low-level cognitive response by exposing individuals in an apparent vegetative state to various stimuli and seeing if physiological measures could pick up any kind of brain activity. What they wound up deciding to do was asking these patients, who they’re not sure if [the patients are] even hearing them or not, to imagine themselves in a tennis match hitting the ball over the net back and forth. In some of these patients, [the test] led to some interesting brain activity. To try to figure out whether consciousness existed at all in a patient, physicians had to pick something that was both familiar and resonant with these individuals, and they turned to sports. They turned to tennis. This idea that there’s a “tennis test” to determine consciousness among potentially vegetative patients [is] fascinating.

Sam Sommers is associate professor of psychology and director of the Diversity & Intergroup Relations Labat Tufts University in Medford, MA. He is interested in issues related to stereotyping, prejudice, and group diversity. His research focuses on race and social perception, judgment and interaction, and the intersection of psychology and law.